CN-121972097-A - Fluidized bed online ash discharging system suitable for silicon tetrachloride cold hydrogenation device

CN121972097ACN 121972097 ACN121972097 ACN 121972097ACN-121972097-A

Abstract

The invention relates to the technical field of polysilicon production, in particular to a fluidized bed online ash discharging system suitable for a silicon tetrachloride cold hydrogenation device, which comprises fluidized bed equipment, an ash collecting tank, a filter and an ash discharging tank. The lower part of the fluidized bed equipment is provided with a discharge port which is communicated with an input port of the ash collecting tank through a first pipeline, and the first pipeline is provided with an ash collecting valve. The top of the ash collecting tank is provided with a pressure equalizing port and a pressure relief port, the pressure equalizing port is communicated with the fluidized bed through a pipeline II, the pipeline II is provided with a pressure equalizing valve, the pressure relief port is communicated with a filter through a pipeline III, the pipeline III is provided with a pressure relief regulating valve, the filter is provided with a hydrogen back-blowing port and a pressure relief pipeline communicated with a regenerated hydrogen pipe network, and a filtering pressure relief valve is arranged. The discharging port of the ash collecting tank is communicated with the feeding port of the ash discharging tank through a pipeline IV, and the ash discharging tank is provided with a pressure relief port, a hydrogen input port and an ash discharging port. The invention realizes the online continuous discharge of the impurities of the fluidized bed, does not interfere with the fluidization quality and the reaction efficiency, and ensures the efficient and stable operation of the cold hydrogenation device.

Inventors

ZHAO XUDONG
PAN HEPING
LI DEQING
GUO WENBIN

Assignees

新疆大全新能源股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260316

Claims (8)

1. The fluidized bed online ash discharging system suitable for the silicon tetrachloride cold hydrogenation device is characterized by comprising fluidized bed equipment, an ash collecting tank, a filter and an ash discharging tank; A discharge hole is formed in the lower part of the fluidized bed equipment; the input port of the ash collecting tank is communicated with the discharge port through a first pipeline which is provided with an ash collecting valve; The top of the ash collection tank is provided with a uniform port and a pressure relief port, the pressure equalizing port is communicated with the fluidized bed equipment through a pipeline II, and the pipeline II is provided with a pressure equalizing valve; The filter is communicated with a pressure relief opening of the ash collection tank through a pipeline III, and a pressure relief regulating valve is arranged on the pipeline III; The filter is provided with a hydrogen back-blowing port; the filter is provided with a pressure relief pipeline which is used for communicating with a regenerated hydrogen pipe network, and a filtering pressure relief valve is arranged on the pressure relief pipeline; the feeding port of the ash discharge tank is communicated with the discharging port of the ash collection tank through a pipeline IV, and an ash collection discharging valve is arranged on the pipeline IV; The pressure relief opening of the ash discharge tank is communicated with the ash collection tank through a pipeline V, and an ash discharge pressure relief valve is arranged on the pipeline V; the hydrogen input port of the ash discharge tank is communicated with the discharging port of the filter through a pipeline six, and a filtering discharging valve is arranged on the pipeline six; A hydrogen replacement pipeline is arranged on the ash discharge tank; the ash discharge tank is provided with a nitrogen replacement input port; the bottom of the ash discharge tank is provided with an ash discharge and blanking port, and the ash discharge and blanking port is provided with an ash discharge and blanking valve.
2. The fluidized bed on-line ash discharging system suitable for the silicon tetrachloride cold hydrogenation device according to claim 1, which further comprises an ash discharging screw conveyor; the ash discharge screw conveyor is communicated with the ash discharge blanking port through a pipeline seven.
3. The fluidized bed on-line ash discharging system suitable for the silicon tetrachloride cold hydrogenation device according to claim 1, wherein, And a ceramic filter element is arranged in the filter.
4. The fluidized bed on-line ash discharging system suitable for the silicon tetrachloride cold hydrogenation device according to claim 1, wherein, The two ash collecting valves are connected in series on the first pipeline.
5. The fluidized bed on-line ash discharging system suitable for the silicon tetrachloride cold hydrogenation device according to claim 1, wherein, The pressure equalizing valves are connected in series on the second pipeline.
6. The fluidized bed on-line ash discharging system suitable for the silicon tetrachloride cold hydrogenation device according to claim 1, wherein, The pressure relief regulating valves are connected in series on the pipeline III.
7. The fluidized bed on-line ash discharging system suitable for the silicon tetrachloride cold hydrogenation device according to claim 1, wherein, The two dust collecting and discharging valves are connected in series on the pipeline IV.
8. The fluidized bed on-line ash discharging system suitable for the silicon tetrachloride cold hydrogenation device according to claim 1, wherein, The two ash discharge pressure relief valves are connected in series on the pipeline five.

Description

Fluidized bed online ash discharging system suitable for silicon tetrachloride cold hydrogenation device Technical Field The invention relates to the technical field of polysilicon production, in particular to a fluidized bed online ash discharging system suitable for a silicon tetrachloride cold hydrogenation device. Background In the production of polysilicon, cold hydrogenation technology is a key step in the improvement of siemens process, and the core of the cold hydrogenation technology is to convert silicon tetrachloride (SiCl 4) into trichlorosilane (SiHCl 3) through a gas-solid heterogeneous reaction. The reaction is usually carried out under high temperature and high pressure conditions, using metallurgical grade silicon powder and copper based catalyst to ensure higher conversion efficiency. However, during long-term operation of the cold hydrogenation apparatus, impurities (such as Fe, al, ca, etc.) in the fluidized bed are gradually enriched, resulting in instability of the bed, which becomes a bottleneck affecting stable operation of the apparatus. Accumulation of impurities causes the following problems: 1. The product is polluted, impurity particles easily enter a chlorosilane product system, the subsequent purification burden is increased, equipment can be blocked, and the normal operation of the device is influenced, 2, the conversion efficiency is reduced, the SiCl 4 conversion rate is reduced due to the fact that the impurity covers the active site of the catalyst, the trichlorosilane yield is influenced, the energy consumption is increased, 3, the device is stopped in an unplanned mode, and the operation efficiency of the device is influenced due to the fact that frequent stoppage and overhaul are needed for removing the impurity, so that the economic loss is caused. At present, the impurity problems are mainly solved by adjusting process parameters or stopping ash discharge in the industry, but the problems of complex operation, low efficiency, high cost and the like exist in the methods. Disclosure of Invention In view of the above, the invention provides a fluidized bed online ash discharging system suitable for a silicon tetrachloride cold hydrogenation device, which mainly aims to realize online continuous discharge of impurities in the fluidized bed, avoid interference with fluidization quality and reaction efficiency, and ensure efficient and stable operation of the cold hydrogenation device. In order to achieve the above purpose, the present invention mainly provides the following technical solutions: the embodiment of the invention provides a fluidized bed on-line ash discharging system suitable for a silicon tetrachloride cold hydrogenation device, which comprises fluidized bed equipment, an ash collecting tank, a filter and an ash discharging tank; A discharge hole is formed in the lower part of the fluidized bed equipment; the input port of the ash collecting tank is communicated with the discharge port through a first pipeline which is provided with an ash collecting valve; The top of the ash collection tank is provided with a uniform port and a pressure relief port, the pressure equalizing port is communicated with the fluidized bed equipment through a pipeline II, and the pipeline II is provided with a pressure equalizing valve; The filter is communicated with a pressure relief opening of the ash collection tank through a pipeline III, and a pressure relief regulating valve is arranged on the pipeline III; The filter is provided with a hydrogen back-blowing port; the filter is provided with a pressure relief pipeline which is used for communicating with a regenerated hydrogen pipe network, and a filtering pressure relief valve is arranged on the pressure relief pipeline; the feeding port of the ash discharge tank is communicated with the discharging port of the ash collection tank through a pipeline IV, and an ash collection discharging valve is arranged on the pipeline IV; The pressure relief opening of the ash discharge tank is communicated with the ash collection tank through a pipeline V, and an ash discharge pressure relief valve is arranged on the pipeline V; the hydrogen input port of the ash discharge tank is communicated with the discharging port of the filter through a pipeline six, and a filtering discharging valve is arranged on the pipeline six; A hydrogen replacement pipeline is arranged on the ash discharge tank; the ash discharge tank is provided with a nitrogen replacement input port; the bottom of the ash discharge tank is provided with an ash discharge and blanking port, and the ash discharge and blanking port is provided with an ash discharge and blanking valve. Further, the device also comprises an ash discharge screw conveyor; the ash discharge screw conveyor is communicated with the ash discharge blanking port through a pipeline seven. Further, a ceramic filter element is arranged in the filter. Further, the number of the ash collecting valves is tw